Nine women have since accused the Republican nominee of unwanted touching or kissing. The ninth, Cathy Heller, told the Guardian on Saturday Trump “grabbed me and went for my mouth and went for my lips”.

Trump has denied all the claims, and also called his accusers “horrible, horrible liars” and, in some cases, demeaned their physical appearance. “Believe me, she would not be my first choice, that I can tell you,” he said of one woman on Friday.

The Little Trump frankly gets out … is stupid … and I don’t defend him when he wanders off. I’ve told him over and over

Newt Gingrich

“I believe Donald Trump,” Giuliani said on Sunday. “I don’t know the nine women, I don’t know the case, I’m not going to engage in Clinton-type conduct and attack them.”

He did, however, question the credibility of two of the women who have come forward, including Jessica Leeds, who spoke to the New York Times. “Some of these things appear to be on their face to be kind of untrue,” Giuliani said, “[such as] 15 minutes of groping in first class on an airplane.”

A self-professed witness emerged on Friday to question the claims by Leeds, which relate to alleged events on a flight in the early 1980s. Reports in the UK have in turn questioned the character and background of the British witness, Anthony Gilberthorpe, a 54-year-old former conservative activist.

“You don’t pick who the witnesses are,” Giuliani said. “This man’s come forward on his own and said it’s not true.”

Gloria Allred, an attorney for a Summer Zervos, a former Apprentice contestant who has accused Trump, held a press conference later on Sunday to answer his attacks against her client and the other women.

“Mr Trump’s terrible smear campaign has been aimed at these brave women because they had the courage to come forward and reveal what they claim he did to them,” Allred said in a statement, “after his own words condemned him.”

Allred also had Ann Russo, a social worker and friend of Zervos, come forward with a public statement that she heard Zervos’ story in 2010, long before Trump’s presidential campaign.

“Summer told me that he was verbally, physically, and sexually aggressive with her and that she had rebuffed his advances,” Russo said, adding that her friend had felt “conflicted” and “believed, at the time, that Mr Trump knew he made a mistake.”

Before the presidential debate in St Louis last Sunday, Trump held a press conference with three women who are critical of Hillary Clinton for her conduct toward accusers of her husband and one who was the alleged victim in a 1975 rape trial in which Clinton represented one of the accused.

Gingrich also voiced frustration. He said he saw “a big Trump” and “a little Trump”. “The Big Trump is a historic figure,” he said, who “is creating issues that make the establishment very uncomfortable.

“The Little Trump frankly gets out – is stupid. I mean, that comment just then is dumb. And I don’t defend him when he wanders off. I’ve told him over and over. You know, presidents have to be disciplined, and in that sense Hillary is probably better trained to be president, just because she’s the most corrupt person to ever get the nomination of a major party.”

Other Trump supporters sought to cast doubt on the women’s claims and whether the media should report them. On CNN on Sunday, Renee Ellmers, a Republican representative from North Carolina, said: “It is a ‘he said, she said’ situation.”

“To correct you,” host Jake Tapper interjected, “it’s a ‘he said, she said, she said, she said, she said, she said, she said, she said, she said, she said’ situation.”

Mike Pence, Trump’s running mate, said the allegations were “unsubstantiated” and that he believed the nominee when he said the recording was “just talk”. Pence told NBC’s Meet the Press it was “necessary to move beyond the issue”.

A Washington Post/ABC poll released on Sunday suggested some voters may have done so. Though Clinton took big leads in some battleground states after the debate, prompting her to discuss the prospect of a landslide victory, the new nationwide poll showed her with just a 47% to 43% lead over Trump. The Libertarian Gary Johnson polled at 5%, and the Green party’s Jill Stein at 2%.

In the same poll, however, 35% of respondents said events since the release of the Access Hollywood tape had made them less likely to vote for Trump. 64% said it would make no difference and 1% said events had made them more likely to vote for the Republican.

A CBS poll, also released Sunday, showed Clinton up 46%-40% in 13 key states, with a 15-point advantage among women.